Since I don't know the 'bastion secret story' in detail, it could potentially have elements such as a secret passage within the bastion. Maybe there's a character in the story who discovers this passage and through it uncovers a long - lost secret about the bastion's origin or purpose.
I'm afraid I can't really share details of the 'bastion secret story' as we don't have much information about it. However, if we assume it's a story set in a medieval - like world, the bastion could be a castle - like structure. The secret story might involve a forbidden love affair between a noble in the bastion and a commoner. The secrecy could be due to the strict social hierarchy of the time, and the story could unfold with various twists and turns as they try to keep their relationship hidden while dealing with the politics and power struggles within the bastion.
Sorry, I don't have enough information to share details of the 'bastion secret story' as it's not a well - known common story to me.